Sadly, they aren't readily available in South Africa and require a special import which makes them a tad expensive. With careful budgeting and lots of patience I'm slowly building up a small collection. I'm not sure how many of these I'll manage to get in the end, but, at the very least, I'll definitely try to get my favourite ones.
My latest acquisitions are Feet of Clay and Men at Arms. The photos really don't do them any justice. I love how the shiny foil is used to enhance the illustrations on the covers.
I've also ordered a copy of Mort, but it seems to have gotten lost on an adventure. It's been more than 50 days since I ordered it and it's still a no-show. Hopefully it will get here eventually.
So at the moment I have a glorious collection of three Gollancz Discworld edtions. (Yes, three totally qualifies as a collection!). I'll better go chain them down... just to be safe.